The preparation of alkali metal salts of polyamides and solutions thereof in dimethylsulfoxide is well known. For example M. Takayanagai and T. Katayose in J. Polym. Sci., Polym. Chem. Ed., vol. 19, 1133-1145 (1981) describe the preparation of the sodium salt of poly(p-phenylene terephthalamide) (hereinafter PPTA) by the reaction of sodium hydride in dimethylsulfoxide (hereinafter DMSO). These sodium salts were used to N-alkylate the polymer by the reaction of a polyarylamide with the appropriate hydrocarbyl halide. The same authors used the same polyarylamides to graft other polymers to PPTA, J. Polym. Sci., Polym. Chem. Ed., vol. 21, 31-39 (1983).
U.S. Pat. No. 4,785,038 describes the dissolution of polyamides in solutions containing certain sodium or potassium bases, a liquid sulfoxide, and water or an alcohol.
U.S. Pat. No. 4,824,881 describes a method for deprotonating polyamides with an alkali metal alkoxide or amide to form a polyarylamide polyanion solution in a liquid sulfoxide.
In all of the above references the only cations specifically mentioned or used are alkali metal cations. There is no mention or use of quaternary ammonium cations as the counterions for polyarylamides. In order to form useful articles from the above polyarylamide alkali metal salts it is necessary to neutralize the salts and preferably remove as much of the ionic impurities (the alkali metal salts from the neutralization) as possible, since such ionic impurities are usually deleterious in the final use of such parts. Even traces of such ionic impurities are especially deleterious, for example, in electrical and electronic uses. It is usually difficult to wash out the last traces of such ionic impurities.
H. Bodaghi et. al., Polym. Eng. Sci., vol. 24, 242-251 (1984); H. Aoki, et. al., Polym. Eng. Sci., vol. 20, 221-229 (1980); J. E. Flood, et. al., J. Appl. Polym. Sci., vol. 27, 2965-2985 (1982) all describe the preparation of films and other parts from sulfuric acid solutions of PPTA. The "coagulants" used in these processes, usually water or lower alcohols, serve not only to coagulate the polymer from the sulfuric acid solution but also to wash the corrosive and ionic sulfuric acid from the coagulated polymer.
It is an object of the present invention to provide quaternary ammonium polyarylamides formed from quaternary ammonium bases and polyamides. It is a feature of the present invention (to provide unique polyarylamides) as well as processes for the preparation thereof and for the development of polymeric articles, the resulting polyamide articles being substantially devoid of ionic impurities. An advantage of the present invention is its usefulness in forming shaped articles having minimal ionic impurities, such as electronic circuit boards and the like. These and other objects, features and advantages of the present invention will become readily apparent upon having reference to the following description of the invention.